Gene regulation, environmental adaptation, and parallel expression divergence in Mus musculus domesticus
Authors: Sylvia Durkin; Mallory Ballinger; Michael Nachman
Affiliation: University of California, Berkeley, Berkeley, CA
Keywords: Comparative genomics & genome evolution
Gene regulatory divergence has long been appreciated as an important driving force of adaptive evolution. This divergence can be in cis-regulatory elements, which act locally, in an allele-specific manner, or trans-regulatory elements, which act distally, potentially affecting many genes. While the relative contribution of cis- and trans-acting regulation to expression divergence is a well-studied topic in evolutionary biology, few studies have investigated the evolution of gene regulatory mechanisms within the context of parallel adaptation. Here we use RNAseq of two wild-derived house mouse lines that independently adapted to northern, temperate environments and compare these to one southern, tropical-adapted line to address several open questions relating to gene regulatory evolution. To what extent are gene expression changes shared between cases of parallel adaptation? What is the relative contribution of cis- and trans- changes to adaptive evolution? Are cis- or trans- changes more likely to contribute to parallel expression divergence? This study in house mice represents one of the shortest divergence times to be investigated for the relative amount of cis- and trans-acting regulation (~500 generations), allowing us to understand the gene regulatory mechanisms involved in adaptive evolution at the earliest stages of divergence.